Electric lamp



Aug. 23, 1932. H. A. DOUGLAS ELECTRIC LAMP Filed Oct. 25, 1929 2 Sheets-Sheet 1 H. A. DOUGLAS ELECTRIC LAMP v Filed 00v. 2:5. 1929 .2 Sheets-Sheet 2 Patented Aug. 23, 1932 UNITED STATES HARRY A. DOUGLAS, 01' 330118011, IICHTGAN mm Lnrr Application filed October 23, 1828. Serial No. 401,720.

My invention relates to lamps which employ lamp receiving sockets and holders for the sockets. The invention is of particular importance where such a lamp is equipped with a concave reflector which carries the holder whose bore is in register with an opening provided through the reflector. The invention has for its eneral object the provision of means wherehy the lamp may be fixed with respect to said holder and, where the lamp is equipped with a reflector, may be fixed with respect to the latter element, also. The invention finds particular use in connection with lamps having parabolic reflectors and enables the fixed relationship of the lamp filament with respect to the parabolic axis on which the filament is preferably located. A lamp thus constructed will direct light in a fixed path with respect to the axis of the refiector, thereby'avodin-g difiiculty now frequently encountered in the ada tation of refleeting lamps to automotive ve icles, bodily or other adjustment of the lamps having frequently been required when the users happen to find that the light is improperly directed.

In my copendlng application Serial No. 403,613 filed October 30, 1929 (case 256), I have broadly claimed a lamp receiving socket within a holder and smaller in cross section than the holder, and means pressing the socket laterally against one side of the holder. The structure disclosed in the aforesaid copending application employs a concave reflector with respect to which the socket holder 33 is fixed, the bore of the socket holder being in register with an opening that is formed through the reflector to permit of the insertion of the base of an incandescent lamp.

The structure of the aforesaid application is also inclusive of spaced apart spacing means intervening between the holder and socket in the place at which the socket is pressed against the holder.

The structure disclosed herein is preferably J inclusive of all of the characteristics above generally set forth, but with some of the characteristics of different construction and arrangement. The structure of my resent invention is inclusive of a socket iiolder, a lamp receiving socket within said holder and smaller in cross section than the bore of the holder, an incandescent lamp having its base within the aforesaid socket, this lamp base being smaller in cross section than the bore of the socket, means pressing the socket laterally against one side of the aforesaid holder to position the socket with respect to the holder, and additional means pressing the lamp base against one side of the socket to position the lamp filament with respect to both socket and holder. The means that presses the socket against the holder is preferably a spring or springs integrally formed with the holder. The means that ,presses the lamp base against the socket is also preferably a spring or springs, integrally formed with the socket.

If the holder be associated with a reflector, the position of the lamp filament with respect to the reflector is assured, it being understood that the lamp filaments of the incandescent lamps which are to be used in the structures of my invention preferably occupy predetermined uniform positions with respect to the lamp bases. To further assure 75 the precise positions of the lamps, I desirably provide V-shaped seats in the bayonet slots that receive the bayonet pins upon the lam s, 'so that the lamps are brought to a uni orm position rotatively. The lamp socket, in the structure of my invention, is preferably prevented from having any longitudinal adjustment, so that the spacing of the lamp filament from the reflector is/fixedly determined. This construction obviates the necessity of a special design for the reflector which has hitherto been proposed to procure the same lighting effect with the filament in different positions along the reflector axis. The invention, however, is not to be thus limited.

The invention will be more fully explained in connection with the accompanying drawings showing the preferred embodiment thereof, and in which Fig. 1 is a plan view with a portion of the reflector shown in sec tion; Fig. 2 is a view from' beneath, part of the bulb being broken away; Fig. 3 is a side view; Fig. 4 is a sectional view on line 4-4 of Fig. 1; Fig. 5 is a sectional view on line 100 base.

5-5 of Fig. 4; Fig. 6 is a sectional view on line 6-6 of Fig. 4; Fig. 7 is a perspective view illustrating component parts of the structure in separated relation; and Fig. 8 is a sectional elevation taken through the axis of the parabolic reflector.

' The lamp illustrated includes a housing or back element 1 having a bracket 2 on its bottomside by which it may be assembled with the automotive vehicle or other support, as indicated. The housing or back 1 encloses a parabolic reflector 3 which is formed with a grooved flange 4 at its forward end. This flange is pressed against a rim 5, provided upon the housing, by an assembling ring 6. This assembling ring also presses the light transmitting closure 7, usually of glass, against a gasket 8 which is seated in the flange 4.

The generally cylindrical socket holder 9 has its forward end passed through a circular opening formed through the crown of the reflector, in the embodiment of the in- 'vention shown. The forward end of the holder 9 is formed with flanges 10 and 11 between, which the surrounding edge portion of the reflector is clamped, whereby the holder and reflector are maintained coaxial, in the structure illustrated.

The generally cylindrical lamp socket 12 is held in assembly with and within the holder 9 by the means hereinafter set forth. This socket is preferably formed with a single bayonet slot or channel 13 for receiving a bayonet pin or projection 14 u on the base 15 of an incandescent lamp. pin is maintained in a V-shaped retaining 'seat 13' of the bayonet slot b{ any suitable means, the V-shaped seat lding the lamp from rotative movement. The means illustrated is, inclusive of a coiled spring 16 which surrounds a plunger 17 constituting a circuit terminal and presses forwardly upon the fplunger head 18 and rearwardly-upon the ange 19 of a metallic guiding sleeve 20. This gulding sleeve is mounted upon an insulating disc 21 which is fixedl assembled with and within the rear end of t e socket 12.

The plunger head 18 presses against a contact 22 which is carried by the generally cylindrical lamp base 15 which is made of insulating material. The lamp structure illustrated is a so-called single pole structure, though the invention is not to be thus limited. Where a single pole structure is employed, the contact 22 is upon the axis of the lamp A stifl' leading in wire 24 establishes connection between the contact 22 and one terminal of the filament 25. Another stifl' leading in wire 26 establishesv a connection between the other terminal of the filament and the metallic sheath 27 which surrounds the insulating portion of the lamp base and, from the point of view of my invention, also constitutes a part or enlargement of the lamp his bayonet inclusive of its sheath 27, is smaller, in cross section, than the bore of the socket.

Spaced apart spacing means intervene between the holder 9 and the socket 12. These spacing means are preferably in the form.

of ribs 28 which extend along the holder and socket. Each rib is desirably integrally formed with one'of the elements 9 or 12, both ribs being shown as being integrally formed with the holder. The llbS are spaced less than 180 degrees apart, preferab y 120 degrees apart. The means for pressing the socket 12 against the holder 9 is desirably inclusive of four spring tongues 29 which are integrally formed with the holder 9. These springs are arranged in spaced apart pairs, the springs of each pair bein also spaced apart. The socket 12 is forme with lugs 30 pressed outwardly therefrom. Each lug is snugly received between two longitudinally related springs 29, whereby the socket is prevented from having longitudinal movement, so that the filament of the lamp is fixed longitudinally of the axis of the reflector. By this preferred construction, it is unnecessary to specially design the reflector as would be desirable if the lamp socket were movable alon the lamp axis. The springs 29 engage t e adjacent side of the socket and press the opposite side .of the socket evenly against the ribs 28, the line of pressure being between these ribs. In this way, the axis of the socket is fixed with reect to the reflector. The side 13 of the ayonet slot 13 in the socket12 also constitutes a spring tongue which presses inwardly against the adjacent side of the lamp base. This spring exerts pressure on a line between the ribs 31 that are shown as being formed upon the lamp base and len hwise thereof. These ribs engage the soc et and accurately define the position of the lamp lengthwise .of the structure. shaped bayonet seat 13 prevents rotativ'e movement of the lam the filament of the lamp is accurately positioned with respect to the reflector, this position being predetermined if the filaments of all lamps to be used in my device are accurately positioned with respect to the lamp bases.

Changes may be made without departing from the invention.

Having thus described my invention, I claim:

1. The combination with a socket holder; of a lamp receiving socket within said holder and smaller in cross section than the bore of As the V- the holder; an incandescent lamp having its ments in the place at which the lamp base is base within said socket, said lamp base being pressed against the socket.

smaller in cross section than the bore of the socket; a bayonet pin on said lamp base; a V-shaped bayonet seat in said socket for said pin: means pressing said pin against said seat; spacing ribs extending longitudinally of the holder and socket and intervening between said holder and said socket; spacing ribs extending longitudinally of the socket and lamp base and intervening between said socket and said lamp base, the ribs intervening between the holder and the socket being in register with the ribs intervening between the socket and the lamp base; a pair of spring tongues on said holder adapted to press against said socket; a formation on said socket adapted to be engaged between said tongues to prevent longq'tudinal movement of the socket in the holder; and a spring tongue on said socket adapted to press against said lamp base.

2. The combination with a socket holder; of a lamp receiving socket within said holder and smaller in cross section than the bore of the holder; an incandescent lamp having its base within said socket, said lamp base being smaller in cross section than the bore of the socket; spacing ribs extending longitudinally of the holder and socket and intervening between said holder and said socket; spacing ribs extending longitudinally of the socket and lamp base and intervening between said socket and said lamp base, the ribs intervening between the holder and the socket being in register with the ribs intervening between the socket and the lamp base; a pair of spring tongues on said holder adapted to press against said socket; a formation on said socket adapted to be engaged between said tongues to prevent longitudinal movement of the socket in the holder; and a spring tongue on said socket adapted to press against said lamp base.

3. The combination with a socket holder; of a lamp receiving socket within said holder and smaller in cross section than the bore of the socket; an incandescent lamp having its base within the aforesaid socket, said lamp base being smaller in cross section than the bore of the socket spring means integral with the holder pressing the socket laterally against one side of the aforesaid holder to position the socket with respect to the holder;

spring means integral with the socket pressing the lamp base against one side of the socket to position the lamp filament with respect to both socket and holder; spacing ribs extending longitudinally of the holder and socket and intervening between these elements in the place at which the socket is pressed against the holder; and spacing ribs extending longitudinally of the socket and lamp base and intervening between these ele- HARRY A. DOUGLAS.

my name. 

